/*
 * Copyright (c) 2002-2009 Moxie Marlinspike
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 3 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
 * USA
 */

#ifndef __BRIDGE_H__
#define __BRIDGE_H__

#include <boost/asio.hpp>
#include <boost/enable_shared_from_this.hpp>
#include <boost/shared_ptr.hpp>
#include <boost/bind.hpp>

#include "Logger.hpp"

#define BUFFER_SIZE 4096

using namespace boost::asio;

class Bridge : public boost::enable_shared_from_this<Bridge>
{

public:
	typedef boost::shared_ptr<Bridge> ptr;

	virtual void close() = 0;
	virtual ip::tcp::socket& getClientSocket() = 0;
	virtual ip::tcp::socket& getServerSocket() = 0;
	virtual void shuttle() = 0;

private:
	ip::tcp::socket *clientSocket;
	ip::tcp::socket *serverSocket;

	void read(ip::tcp::socket *socket, char *buffer)
	{
		socket->async_read_some(boost::asio::buffer(buffer, BUFFER_SIZE),
		                        boost::bind(&Bridge::readComplete,
		                                    shared_from_this(), socket, buffer,
		                                    placeholders::error,
		                                    placeholders::bytes_transferred));
	}

	void readComplete(ip::tcp::socket *socket, char *buffer,
	                  const boost::system::error_code& error, size_t bytesRead)
	{
		if (!error)
		{

			if (socket == clientSocket)
				processClientInput(buffer, bytesRead);

			async_write((socket == clientSocket) ? *serverSocket : *clientSocket,
			            boost::asio::buffer(buffer, bytesRead),
			            boost::bind(&Bridge::writeComplete, shared_from_this(),
			                        socket, buffer, placeholders::error));

		}
		else if (error != error::operation_aborted)
		{
			std::stringstream errorStream;
			errorStream << "Read error: " << error;
			std::string error = errorStream.str();
			Logger::logError(error);
			close();
		}
	}

	void writeComplete(ip::tcp::socket *socket, char *buffer,
	                   const boost::system::error_code &error)
	{
		if      (!error)                                         read(socket, buffer);
		else if (error != error::operation_aborted) close();
	}

protected:
	char clientBuffer[BUFFER_SIZE];
	char serverBuffer[BUFFER_SIZE];

	virtual void processClientInput(char *buffer, int length) = 0;

	void shuttle(ip::tcp::socket *clientSocket,
	             ip::tcp::socket *serverSocket)
	{
		this->clientSocket = clientSocket;
		this->serverSocket = serverSocket;

		read(clientSocket, clientBuffer);
		read(serverSocket, serverBuffer);
	}

	ptr getSmartPointer()
	{
		return shared_from_this();
	}

};


#endif
